The general hypothesis to be tested by this research plan is that the central integration of cardiovascular reflexes arising from receptors in the carotid sinus, carotid body, and heart, occurs in specific areas of the central nervous system. It is also hypothesized that the primary, secondary and tertiary neurons are specific for each group of afferents. The specific aims are to determine: 1) the central integration of some specific cardiovascular reflexes using the (14C) deoxyglucose functional brain mapping technique of Sokoloff. The initial studies, in sodium pentobarbital anesthetized cats, will map the functional brain pathways of the physiologically stimulated carotid sinus reflex; 2) the central functional projections of the physiologically stimulated carotid body reflex and to compare the functional pathways of this reflex with those of the carotid sinus reflex; 3) the functional central projections of the left ventricular cardiac vagal afferents which elicit the Bezold-Jarisch reflex and to compare these functional pathways with those of the carotid sinus andjjcarotid body reflexes; 4) the functional central projections of the right ventricular vagal afferents and to compare their projections with those of the left ventricular vagal afferents and the carotid sinus and carotid body afferents; 5) the level of background glucose metabolic activity of all levels of the central nervous system in a group of sodium pentobarbital anesthetized cats that have been prepared surgically in an identical manner to those in the experimental group. These studies have the potential of yielding much new information concerning which areas of the brain are associated with neural control of the circulation. Ultimately, the results from these studies could contribute to the development and implementation of new neuropharmacological therapeutic strategies for the treatment of patients with abnormal cardiovascular function.